﻿
public class Circle extends Shape{

    public double radius;

    public Circle(){
        this.type = "圆";
    }

    public void calculate(){
        //计算圆的面积是 π * R²;
        this.area = Math.PI * Math.pow(radius , 2);
    }

    public void description(){
        //输出圆的半径和面积
        System.out.println("圆的半径为 : " + radius);
        show();
    }

}
